1Overview

The LocalTime scalar type represents a time of day without date or time zone information. It is intended for scenarios where only the time component matters, such as business operating hours (e.g., “opens at 09:00”), daily schedules, or recurring time-based events where the specific date is irrelevant.

Unlike instant-based DateTime scalars that represent a specific moment in time, LocalTime represents a wall-clock time that could refer to different moments depending on the date and time zone context applied to it. This makes it suitable for applications where only the time of day is meaningful.

The scalar uses RFC 3339 format for serialization, specifically the partial-time production.

2Recommended name

The recommended name for this scalar is LocalTime.

3Result spec

A LocalTime scalar must serialize to a string conforming to the RFC 3339 partial-time production. This represents a time of day in the format: HH:mm:ss or HH:mm:ss.fffffffff (with optional fractional seconds).

The format is:

• HH: Two-digit hour (00-23)
• mm: Two-digit minute (00-59)
• ss: Two-digit second (00-59)
• .fffffffff: Optional fractional seconds (up to 9 digits for nanosecond precision)

The serialized value must not include time zone offset information.

4Input spec

A LocalTime scalar accepts string values conforming to the RFC 3339 partial-time production, both as GraphQL literals and as JSON input values.

The input format matches the result format and must:

• Follow the pattern HH:mm:ss or HH:mm:ss.fffffffff
• Not include time zone offset information (Z or +/-HH:mm)
• Contain valid time values per RFC 3339

Implementations should validate:

• Hour is between 00 and 23
• Minute is between 00 and 59
• Second is between 00 and 59 (leap seconds are not supported)
• Fractional seconds, if present, are numeric (up to 9 digits)

mutation {
  setBusinessHours(openingTime: "09:00:00", closingTime: "17:00:00") {
    id
  }
}

{
  "openingTime": "09:00:00"
}

{
  "alarmTime": "07:30:00.500"
}

5References

• RFC 3339 — Date and Time on the Internet: Timestamps